The processing of biological materials is of considerable significance for analytical purposes.
Automated liquid handling devices are commonly used in such processes. Devices are commercially available which may include an automated pipet head assembly movable within the device so that it may be aligned with test tubes or vials for reagent liquid handling.
In some automated liquid handling devices, a pipet head assembly uses disposable pipet tips to aspirate and release samples and reagents. Aspiration and release may be performed according to protocols operated by a dedicated microcomputer. A work surface assembly may be provided which comprises various elements to enable positioning of pipet tips, reagent containers, sample containers and the like. A multiwell format is frequently adopted so that a number of parallel pipetting channels can be employed simultaneously to enable simultaneous processing of a number of samples.
When the automated liquid handling device processes samples, for example so as to purify a molecule from a complex mixture, one of the most striking challenges is that there should be no contamination between vessels such as, e.g., microwells containing one sample and vessels containing another sample. This is commonly referred to as cross-contamination.
Attempts have been made to address this problem, e.g., by a symmetrical setup of a work surface assembly in which the loaded pipets are not passed over unused vessels containing other reagents or samples, as described in GB 2452628.
Document EP 1081234 discloses a liquid waste container with separate sections for the introduction of multiple pipet tips in order to prevent cross-contamination when liquid waste is dispensed into a waste container.
The present invention provides a method for disposing of a liquid within an automated analytical system for processing a fluid biological sample, said method displaying several advantages.